{"id":7794,"date":"2020-02-08T00:00:00","date_gmt":"2020-02-08T00:00:00","guid":{"rendered":""},"modified":"2025-06-17T17:22:34","modified_gmt":"2025-06-17T17:22:34","slug":"dna-analysis-and-facial-reconstruction-of-human-skull","status":"publish","type":"post","link":"https:\/\/www.ukessays.com\/essays\/archaeology\/dna-analysis-and-facial-reconstruction-of-human-skull.php","title":{"rendered":"DNA Analysis and Facial Reconstruction of Human Skull"},"content":{"rendered":"\n
\"SME-led<\/figure>\n\n\n\n

Introduction<\/h2>\n\n\n\n

Box 9 encompassed a complete skull, articulated pelvis and right femur, all from a single, unknown individual. Sex, age, ethnicity, height and pathology was determined using both metric and morphological forensic anthropological methods. Metric analysis is advantageous because it\u2019s easier to learn and reproduce, relies on standard landmarks, and results in fewer indeterminate conclusions (Giles, 1970). However, disadvantages include the need for unfragmented bones and population-specific formulae. Therefore, if remains are burned or fragmented, a qualitative method is needed, however, these can be subjective and lack of consistency (Giles, 1970). Alongside this, facial reconstruction and DNA profiling provided further evidence to help identify this individual.<\/p>\n\n\n\n

Pathological conditions<\/h2>\n\n\n\n

Pathology is important to consider before determining sex, age and ethnicity to prevent bias. This individual has many common characteristics of acromegaly- a rare disorder caused by over-production of growth hormone from the pituitary gland, these include an enlarged skull, protruding mandible, mispositioned teeth and excessive bone outgrowth around sutures (Chapman, 2017).<\/p>\n\n\n\n

Although these features could also indicate gigantism, this individual\u2019s pelvis and femur are within normal ranges, suggesting the condition was acquired in adulthood which only occurs in acromegaly patients (NIDDK, 2012). Acromegaly progression is often linked to type 2 diabetes, hypertension, osteoarthritis and severe muscle weakness, which, if left untreated, could lead to premature death- it may have also caused this individual to have a stooped posture and frequent cardiovascular complications (Chapman, 2017). As the pelvis and femur have no signs of disease or damage, it\u2019s unlikely this individual had osteoarthritis, however, absence of organs and muscles means other conditions cannot be ruled out as cause of death.<\/p>\n\n\n\n

Sex<\/h2>\n\n\n\n

Ferembach\u2019s (1980) qualitative method for skull sex determination indicated most features were hyper-male. However, a rough but medium thickness zygomatic process and a somewhat flexed posterior border of the mandibular ramus showed neither male or female characteristics. Despite this, overall, one can predict that this individual was male.<\/p>\n\n\n\n

Giles and Elliot (1963)<\/h2>\n\n\n\n

Alternatively, Giles and Elliot\u2019s (1963) discrimination function is a quicker method with similar accuracy of 86.6%. Using formula 1, outlined in Appendix D, a value of 2994.9 is obtained, also suggesting this individual was male, increasing reliability of conclusions. Krogman (1962) found that sexing the skull alone is 90% accurate, however, sexing the skull and pelvis together is 98% accurate. Thus, to increase accuracy of final conclusions, the pelvis and femur need to be analysed too.<\/p>\n\n\n\n

The pelvis is the best indicator of sex due to its adaptation for childbirth in females. Phenice\u2019s (1969) morphological technique uses 3 pubis characteristics to determine sex- one of which is the ventral arc, said to be 96% accurate in determining sex (Sutherland and Suchey, 1991). Unfortunately, this technique produced mixed results for this pelvis, therefore, alternatively, Albanese\u2019s (2003) metric analysis, outlined in Appendix B, uses the whole pelvis and femur to increase accuracy and reduce subjectivity of sex determination. Using model 1, which has 98% accuracy, a value of 0.26 is obtained, suggesting this individual was female. Yet, model 2 and 3, which have 97% and 96.3% accuracy respectively, obtain 0.62 and 0.94, clearly indicating male. Although model 2 and 3 have lower accuracy, their matching outcome increases confidence and validity, allowing one to conclude this individual was male.<\/p>\n\n\n\n

Bass (1978)<\/h2>\n\n\n\n

Bass (1978) discovered that a femur head diameter >47.5mm indicates male while <42.5mm indicates female. Unfortunately, as this individual\u2019s is only 44.85mm, sex cannot be determined. Nevertheless, height can be estimated using Trotter\u2019s formula (1970). As femur length is 47.9cm, height is estimated at 175.4 cm \u00b13.27.<\/p>\n\n\n\n

However, cranial suture closure is considered unreliable and inaccurate because it frequently under\u2010ages older adults and over\u2010ages sub-adults (Molleson and Cox 1993). Moreover, this individual\u2019s acromegaly caused excessive outgrowth of bone around the sutures, potentially affecting their closure and, thus, impacting age determination. As a result, a more reliable method of ageing the skull involves looking at dentition.<\/p>\n\n\n\n

Teeth are the least destructible part of the body, making them excellent for age estimation. No deciduous dentition and evidence of tooth 8 alveolar processes indicate this individual was at least 18 years old (Carr, 1962). Dental wear analysis provides more accurate age determination than those previously mentioned because it examines enamel which cannot be remodelled. A widely used method involves analysing of mandibular molar wear (Miles 1963). However, excessive ante- and postmortem tooth loss means only two mandibular molars are present, preventing any valid age estimation.<\/p>\n\n\n\n

These forensic age estimation techniques conclude that this individual could be anywhere between 25 and 48.1 years old. However, after combining all results and analysing their accuracy and validity, it is likely that this individual is between 32 and 43 years old.<\/p>\n\n\n\n

Facial reconstruction<\/h2>\n\n\n\n

During facial reconstruction, 16 osteometric points were measured and attached to the skull, then, facial muscles, features, fat and skin were created from wax to produce a potential antemortem model of this individual. After completion, it was clear that this individual was a male with a very prominent jaw and forehead which links to previous conclusions.<\/p>\n\n\n\n

Despite this, as this is an artistic interpretation completed by a group of untrained individuals without any soft tissue or portrait to work alongside, this method is very subjective and therefore not very reliable at recreating an individual\u2019s morphological traits for identification. Therefore, this could be improved using computerised 3D facial reconstruction.<\/p>\n\n\n\n

DNA profiling<\/h2>\n\n\n\n

Therefore, to find a match, AFLP should be repeated ensuring there is adequate, unfragmented DNA along with an appropriate, high specificity primer. Primer dimers at the bottom of lane 9 suggests the primer concentration was too high, therefore, to avoid allelic dropout which may assume homozygosity, lower concentrations should be used when repeating.<\/p>\n\n\n\n

AFLP requires high quality and quantity of DNA to prevent allelic dropout, however, it\u2019s likely that this cannot be achieved from this DNA sample. Therefore, DNA-17 may provide better results because it requires less DNA due to improved sensitivity and discrimination between profiles (Crown Prosecution Service, 2019).<\/p>\n\n\n\n

Conclusion<\/h2>\n\n\n\n

After analysing all results, one can estimate this was a European male aged between 32 and 43 who was 174cm tall, living with acromegaly. The likely cause of death is co-morbidity associated with acromegaly progression. Unfortunately, these conclusions cannot be confirmed through DNA fingerprinting which reduces validation and reliability, therefore, further analysis to confirm this individual\u2019s identity could include more reliable methods involving molecular biology and bone chemistry.<\/p>\n\n\n\n

References for Human Skull DNA Analysis and Facial Reeconstruction<\/h2>\n\n\n\n

A-K Sources<\/h3>\n\n\n\n